Initial signal detection method and apparatus

Abstract

An initial signal detection method includes performing, by a user equipment, detection on one or more sub-channels on an unlicensed spectrum, and determining, based on a combination of a group common-demodulation reference signal and a group common-physical downlink control channel that is detected by the user equipment a first time, that downlink transmission has started or that a channel occupancy time has started.

What is claimed is: 
     
       1. An initial signal detection method, comprising:
 performing, by a user equipment (UE), detection on one or more sub-channels on an unlicensed spectrum; and 
 determining, based on a combination of a group common-demodulation reference signal (GC-DMRS) and a GC-physical downlink control channel (GC-PDCCH) that is detected by the UE a first time that downlink transmission has started or that a channel occupancy time (COT) has started. 
 
     
     
       2. The method according to  claim 1 , wherein a configuration of a search space of an initial signal of the UE satisfies at least one of the following:
 an aggregation level of the GC-PDCCH in the initial signal is set to a fixed value; or 
 a maximum quantity of blind detection times of the GC-PDCCH in the initial signal is one or two times in each slot. 
 
     
     
       3. The method according to  claim 2 , further comprising:
 receiving configuration information of the search space of the initial signal of the UE, wherein the configuration information includes the configuration of the search space of the initial signal of the UE. 
 
     
     
       4. The method according to  claim 2 , wherein a first UE-specific PDCCH uses a new radio (NR) downlink control information (DCI) 1_0 format. 
     
     
       5. The method according to  claim 1 , wherein the combination of the GC-DMRS and the GC-PDCCH, and that is detected by the UE the first time is located at a symbol 1, 3, or 7 in a slot, and the method further comprises:
 continuing, by the UE, to search a search space of the GC-PDCCH for a first UE-specific PDCCH of the UE. 
 
     
     
       6. The method according to  claim 1 , wherein the combination of the GC-DMRS and the GC-PDCCH, and that is detected by the UE the first time is located at a symbol 0 in a slot, and the method further comprises:
 searching, by the UE, a search space of a UE-specific PDCCH outside of a search space of the GC-PDCCH for the UE-specific PDCCH of the UE. 
 
     
     
       7. An initial signal transmission method, comprising:
 performing, by a network side, listen before talk (LBT) on one or more sub-channels on an unlicensed spectrum; and 
 sending, by the network side, one or more combinations of a group common-demodulation reference signal (GC-DMRS) and a GC-physical downlink control channel (GC-PDCCH) on one or more sub-channels on which the LBT succeeds, wherein one of the one or more combinations of the GC-DMRS and the GC-PDCCH is used as an initial signal for downlink transmission. 
 
     
     
       8. The method according to  claim 7 , a configuration of a search space of an initial signal of one or more user equipment (UEs) satisfies at least the following:
 an aggregation level of the GC-PDCCH in the initial signal is set to a fixed value; or 
 a maximum quantity of blind detection times of the GC-PDCCH in the initial signal is one or two times for each symbol on which detection is performed. 
 
     
     
       9. The method according to  claim 7 , further comprising:
 sending, by the network side, configuration information of the search space of the initial signal of the one or more UEs, wherein the configuration information includes the configuration of the search space of the initial signal of the UE. 
 
     
     
       10. The method according to  claim 7 , wherein
 a first sent combination of the GC-DMRS and the GC-PDCCH is located at a start location of a channel occupancy time (COT). 
 
     
     
       11. The method according to  claim 7 , wherein
 one of the sent one or more combinations of the GC-DMRS and the GC-PDCCH is located at a symbol 1, 3, or 7 in a slot, wherein a search space of the GC-PDCCH comprises a first UE-specific PDCCH of the one or more UEs. 
 
     
     
       12. The method according to  claim 11 , wherein the first UE-specific PDCCH uses a new radio (NR) downlink control information (DCI) 1_0 format. 
     
     
       13. The method according to  claim 7 , wherein one of the one or more combinations of the GC-DMRS and the GC-PDCCH is located at a symbol 0 in a slot, wherein outside of a search space of the GC-PDCCH, a search space of a UE-specific PDCCH comprises one or more UE-specific PDCCHs. 
     
     
       14. A communication apparatus, comprising:
 a non-transitory memory configured to store non-transitory instructions; and 
 one or more processors coupled with the non-transitory memory, wherein the one or more processors are configured to execute the non-transitory instructions to cause the apparatus to: 
 perform detection on one or more sub-channels on an unlicensed spectrum; and 
 determine, based on a combination of a group common-demodulation reference signal GC-DMRS) and a GC-physical downlink control channel (GC-PDCCH) that is detected for a first time, that downlink transmission has started or that a channel occupancy time (COT) has started. 
 
     
     
       15. The apparatus according to  claim 14 , wherein a configuration of a search space of an initial signal of a user equipment (UE) satisfies at least one of the following:
 an aggregation level of the GC-PDCCH in the initial signal is set to a fixed value; or 
 a maximum quantity of blind detection times of the GC-PDCCH in the initial signal is one or two times in each slot. 
 
     
     
       16. The apparatus according to  claim 15 , wherein the one or more processors are configured to execute the non-transitory instructions to further cause the apparatus to receive configuration information of the search space of the initial signal of the apparatus, wherein the configuration information includes the configuration of the search space of the initial signal of the apparatus. 
     
     
       17. The apparatus according to  claim 16 , wherein a first UE-specific PDCCH uses a new radio (NR) downlink control information (DCI) 1_0 format. 
     
     
       18. The apparatus according to  claim 15 , wherein the combination of the GC-DMRS and the and that is detected by the apparatus the first time is located at a symbol 1, 3, or 7 in a slot, and the one or more processors are configured to execute the non-transitory instructions to further cause the apparatus to continue to search a search space of the GC-PDCCH for a first UE-specific PDCCH of the UE. 
     
     
       19. The apparatus according to  claim 15 , wherein the combination of the GC-DMRS and the and that is detected by the apparatus for the first time is located at a symbol 0 in a slot, and the one or more processors are configured to execute the non-transitory instructions to further cause the apparatus to search a search space of a UE-specific PDCCH outside of a search space of the GC-PDCCH for the UE-specific PDCCH of the apparatus.